Guardian G25AMK005, Technical Manual

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G U A R D I A N V H F 1 1 0 W M O B I L E 3-17
3.6.2.2.1 Interrupt Sources
The following interrupt sources are used in H8.
Interrupt Source Description
User interface External interrupt from the keypad
DSP External interrupt from the DSP, signal detected, etc.
Low dc voltage External NMI from power supply indicates power supply fail
Timer Internal time base tick interrupt every 10 ms
PC serial port Internal interrupt from PC interrupt serial port
UI serial port Internal interrupt from user interface serial port, key press, and LCD data
Debug serial port Internal interrupt from DMA/timer
Alarm generator Internal interrupt from DMA/timer
3.6.2.2.2 Polled Inputs
The H8 software polls the following inputs at regular intervals.
Input Description
EXTPTT/RTS External PTT and data RTS
OOL Synthesizer out of lock
PWROFF On/off switch position
SENSE External keyfill device detect
The following analog inputs are measured as appropriate to the radio mode of operation.
Input Description
RSSI Receiver signal strength
WRU External device detect
BATT Main radio 10V supply monitor
PA TEMP Transmitter temperature
XTAL TEMP Reference crystal temperature
PA CURRENT Transmitter current
3.6.2.2.3 Watchdog
A regular watchdog service task is scheduled to prevent the H8 watchdog controller from overrunning, and a
hardware reset from occurring. The target watchdog timeout is 100/200 ms.
3.6.2.3 Start-Up Software
3.6.2.3.1 Boot Block Start-Up Software
The minimum simplest start-up software is provided in the boot block of the Flash. This software holds the keypad,
DSP, user interface, and FPGA in reset, and then establishes whether a valid H8 program image exists in the
program blocks of the Flash. If no valid program exists, a simple alarm sounds. The boot block software includes a
minimum basic BIT facility to check the code itself, and the internal and external random access memory (RAM).
The boot block code includes the software to allow programming of the program blocks through the PC serial port.